Emergency alert signal



FIG. 1 is a perspective view of an emergency alert signal;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines depict unclaimed environmental subject matter. 

The ornamental design for a emergency alert signal, as shown. 